Constancy and variability of gallbladder ejection fraction: impact on diagnosis and therapy.

The main objective of this study was to test the constancy and variability of gallbladder (GB) ejection fraction (EF) in long-term studies to (a) determine whether EF ever becomes normal once it is low, (b) determine how long it takes for the EF to become abnormal once it is found to be normal, (c) explore the cause of low EF, and (d) define objective parameters for biliary and nonbiliary abdominal pain. METHODS: Fifty-two patients (42 women, 10 men) who underwent quantitative cholescintigraphy twice (total studies, 104), over a mean period of 38.54 mo between studies, were chosen for retrospective analysis. They were divided into the following groups: control (n = 13; nonbiliary abdominal pain), chronic acalculous cholecystitis (CAC) (n = 27; biliary abdominal pain), chronic calculous cholecystitis (CCC) (n = 6; biliary abdominal pain), and opioid (n = 6; nonbiliary abdominal pain). The last group had received an opioid before cholecystokinin-8 (CCK-8) infusion in one study but not in the other study. A GBEF value of > or =35% was considered normal with a 3-min infusion and > or =50% as normal with a 10-min infusion of CCK-8. RESULTS: The mean GBEF value was reproducible between the 2 sequential studies in the control group (66.0% +/- 20.5% vs. 73.9% +/- 17.7%), CAC group (24.4% +/- 22.3% vs. 16.9% +/- 10.9%), and CCC group (20.8% +/- 20.9% vs. 27.5% +/- 34.5%) but not in the opioid group (14.8% +/- 14.6% vs. 56.5% +/- 31.7%). The severity of GBEF reduction in CAC increased with time: 7.2% +/- 8.1% within 12 mo, 16.1% +/- 14.9% in 13-47 mo, and 23.5% +/- 21.3% in 48-168 mo. None of the 27 patients with CAC developed a gallstone as detected by ultrasound during the study period. In 5 patients with CAC, a mean period of 52.6 +/- 28.9 mo was required for conversion from normal to a low EF. CCK-induced cystic duct spasm is the etiology for low EF in both CAC and CCC. CONCLUSION: Normal and low GBEF values are reproducible in long-term studies. Once the EF reaches a low value, it does not return to normal, and a normal value requires many years to become abnormal. CCK-induced cystic duct spasm is the cause of low GBEF in CAC and CCC, and the severity of EF reduction is similar for both. Exclusion of opioid intake immediately before the study is critical before attributing a low GBEF value to an irreversible GB motor dysfunction.     

Importance of dosimeter calibration method on nebulizer output.

BACKGROUND: We have observed that dosimeter-run nebulizers have a much smaller output when manually activated than when breath activated; however, this has not been adequately investigated. OBJECTIVE: To evaluate the effect of different calibration methods on nebulizer output. METHODS: Six healthy subjects performed all calibrations. The nebulizers were operated by 2 different dosimeters and were calibrated to produce 9 microL per actuation by breath activation followed by exhalation to the room. The nebulizers were then operated at these identical settings, and the output determined in 3 ways: (1) breath activation followed by exhalation to the room, (2) breath activation with exhalation into the nebulizer, and (3) manual activation (with no subject using the nebulizer). These 3 methods were termed regular, rebreathe, and manual, respectively. RESULTS: There was a large and statistically significant difference in nebulizer output among the 3 methods. The measured rebreathe outputs (5.6 and 5.7 microL per actuation) were approximately two thirds and the manual outputs (3.2 and 3.9 microL per actuation) were approximately one third of the regular calibration outputs (8.6 and 8.9 microL per actuation); the 2 values are for the 2 dosimeters. The results were highly statistically significant (P < .001). CONCLUSIONS: The method by which a nebulizer-dosimeter system is calibrated results in different nebulizer outputs. This has a high likelihood of influencing the concentration of methacholine causing a 20% decrease in volume in the first second of forced expiration.     

Bacteraemia in diabetics

During a period of 22 months one or more episodes of bacteraemia were detected in 168 patients in hospital. Of these, 29% also had diabetes compared with 10% of the total number of patients admitted to hospital during this time (P less than 0.001). The diabetics with bacteraemia were elderly and diabetes had usually been present for many years. Most of them were not receiving insulin at the time bacteraemia was diagnosed. Escherichia coli was the commonest pathogen (33%) in the diabetics, the main source of infection being the urinary tract. This finding may be due to diabetic autonomic neuropathy, which leads to a poorly emptying, chronically infected bladder. Urinary tract infections with bacteraemia in elderly diabetics are often accompanied by vague non-specific symptoms and poor diabetic control. Fever is infrequent. Prompt antibiotic therapy and insulin injections to control the diabetes usually cure these serious infections.     

Pregnancy-induced hypertension: current concepts

This brief review outlines current concepts concerning the aetiology and pathophysiology of pregnancy-induced hypertension and, based upon these concepts, presents a plan of intensive care management for the severe forms of this condition.     

Management activities in community dietetics practice

Information on the management activities of community dietitians was obtained through a mail survey of 350 randomly selected community dietitians. Subjects provided information on their management level, the importance to their job performance of 83 management activity statements, and the percent of time they spent performing management activities in each of nine categories. Twenty-nine percent of the respondents indicated job responsibilities in lower-level management; 45% had mid-level and 26% had upper-level management responsibilities. Numbers of activities rated essential or very important increased as management levels increased. Kinds of activities changed from technical to human to conceptual as management levels increased. Mid-level management subjects, while still spending time working with clients, reported spending considerable time on coordinating, investigating, and evaluating, often reporting as much time spent on those activities as did upper-level management subjects. Definitions provided by respondents indicated great diversity in job requirements and settings.     

Muscarinic suppression of the M-current in the rat sympathetic ganglion is mediated by receptors of the M1-subtype.

1. Under voltage-clamp dissociated adult and foetal rat superior cervical ganglion (s.c.g.) cells exhibited a non-inactivating voltage- and time-dependent component of K+ current termed the M-current (IM). IM was detected and measured from the current decay during hyperpolarizing voltage steps applied from potentials where IM was pre-activated. 2. Neither the resting membrane current nor the amplitude of these current decay relaxations were reduced by omitting Ca from the bathing fluid, showing that the M-current was not a 'Ca-activated' K-current dependent on a primary Ca-influx. Concentrations of (+)-tubocurarine sufficient to block the slow Ca-activated K-current IAHP did not inhibit IM or antagonize the effect of muscarinic agonists on IM, showing that IM was not contaminated by IAHP. Tetraethylammonium (1 mM), which blocks the fast Ca-activated K-current IC, produced a small inhibition of IM. This was not due to contamination of IM by IC since muscarinic agonists did not consistently block IC. 3. The muscarinic agonists muscarine, oxotremorine, McN-A-343 and methacholine reversibly suppressed IM, resulting in an inward (depolarizing) current. The rank order of potency was: oxotremorine greater than or equal to muscarine greater than McN-A-343 greater than methacholine. 4. The suppression of IM by muscarine was similar in cultured cells derived from adult and foetal tissue to that seen in the intact ganglia. 5. IM-suppression by muscarine was inhibited by pirenzepine (Pz) and AF-DX 116 with mean pKB values of 7.53 +/- 0.13 (n = 3) and 6.02 +/- 0.13 (n = 4) respectively. 6. The suppression of IM by muscarinic agonists was not affected by gallamine (10-30 microM). 4-Diphenylacetoxy-N-methylpiperidine methiodide inhibited the response at 300 nM. 7. Pirenzepine inhibited the contractions of the guinea-pig isolated ileum produced by muscarine with a mean pKB of 6.37 +/- 0.03 (n = 8). 8. These results suggest that the receptors mediating suppression of the M-current accord with those designated pharmacologically as M1 and that these receptors reach maturity at a very early stage in the development of the rat s.c.g.     

Lack of concordance of growth rates of primary and recurrent breast cancer

The degree of concordance of growth rates of primary tumors with corresponding recurrences was investigated by using data from 184 patients with breast cancer with measurable recurrences. For conduction of this examination, the detection processes of both the primary tumor and the recurrence were explored. The probability of detection of a recurrence per unit time was found to be nearly proportional to the tumor's diameter. Approximately 60,000 cells initiated the recurrence, and the distribution of doubling times of the recurrences was exponential, with a mean of 2.1 months. The probability of detection of the primary tumor per unit time was approximately proportional to its volume. The distribution of doubling times of primary tumors was nearly exponential; from other evidence, we inferred that the mean doubling time was also close to 2.1 months. Several techniques to measure growth rate agreement between the primary and recurrent tumors within individuals were developed, and all of them yielded the result that the growth rates are nearly unrelated.     

Diurnal variation of intraocular pressure and the overriding effects of sleep

Intraocular pressure (IOP) was recorded regularly over a 24-h period in 13 normal subjects. All subjects showed a dramatic rise in IOP after sleep, ranging from 37 to 248%. In a second experiment, IOP decreased when 15 subjects remained upright and awake throughout the night. When sleep was not permitted IOP was lowest at 3:00 a.m. (0300); when six of these subjects were permitted to sleep from 0600 to 0800, they showed a rapid and significant increase in IOP of up to 150%, whereas the remaining nine subjects showed (posturally induced) increases of up to 38%.